treewide: mark some functions static

These were found by enabling the "missing-declarations" warning.

spa/examples/adapter-control.c

@@ -176,7 +176,7 @@ exit_cleanup:
 	return res;
 }
 
-int init_data(struct data *data)
+static int init_data(struct data *data)
 {
 	int res;
 	const char *str;

spa/examples/example-control.c

@@ -457,7 +457,7 @@ static int load_handle(struct data *data, struct spa_handle **handle, const char
 	return -EBADF;
 }
 
-int init_data(struct data *data)
+static int init_data(struct data *data)
 {
 	int res;
 	const char *str;

spa/plugins/audioconvert/fmt-ops-avx2.c

@@ -132,7 +132,7 @@ conv_s16_to_f32d_2_avx2(struct convert *conv, void * SPA_RESTRICT dst[], const v
 	}
 }
 
-void
+static void
 conv_s24_to_f32d_1s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA_RESTRICT src,
 		uint32_t n_channels, uint32_t n_samples)
 {
@@ -308,8 +308,7 @@ conv_s24_to_f32d_avx2(struct convert *conv, void * SPA_RESTRICT dst[], const voi
 		conv_s24_to_f32d_1s_avx2(conv, &dst[i], &s[3*i], n_channels, n_samples);
 }
 
-
-void
+static void
 conv_s32_to_f32d_4s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA_RESTRICT src,
 		uint32_t n_channels, uint32_t n_samples)
 {
@@ -375,7 +374,7 @@ conv_s32_to_f32d_4s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA
 	}
 }
 
-void
+static void
 conv_s32_to_f32d_2s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA_RESTRICT src,
 		uint32_t n_channels, uint32_t n_samples)
 {
@@ -423,7 +422,7 @@ conv_s32_to_f32d_2s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA
 	}
 }
 
-void
+static void
 conv_s32_to_f32d_1s_avx2(void *data, void * SPA_RESTRICT dst[], const void * SPA_RESTRICT src,
 		uint32_t n_channels, uint32_t n_samples)
 {

spa/plugins/audioconvert/fmt-ops-sse2.c

@@ -315,8 +315,7 @@ conv_s24_to_f32d_sse2(struct convert *conv, void * SPA_RESTRICT dst[], const voi
 		conv_s24_to_f32d_1s_sse2(conv, &dst[i], &s[3*i], n_channels, n_samples);
 }
 
-
-void
+static void
 conv_s32_to_f32d_1s_sse2(void *data, void * SPA_RESTRICT dst[], const void * SPA_RESTRICT src,
 		uint32_t n_channels, uint32_t n_samples)
 {

spa/plugins/bluez5/backend-native.c

@@ -2708,7 +2708,7 @@ static void set_call_setup(enum call_setup value, void *user_data)
 	}
 }
 
-void set_battery_level(unsigned int level, void *user_data)
+static void set_battery_level(unsigned int level, void *user_data)
 {
 	struct impl *backend = user_data;
 

spa/plugins/bluez5/backend-ofono.c

@@ -307,7 +307,7 @@ static const struct spa_bt_transport_implementation ofono_transport_impl = {
 	.release = ofono_audio_release,
 };
 
-bool activate_transport(struct spa_bt_transport *t, const void *data)
+static bool activate_transport(struct spa_bt_transport *t, const void *data)
 {
 	struct impl *backend = (void *)data;
 	struct transport_data *td = t->user_data;

spa/plugins/bluez5/iso-io.c

@@ -308,7 +308,7 @@ static void group_destroy(struct group *group)
 	free(group);
 }
 
-struct stream *stream_create(struct spa_bt_transport *t, struct group *group)
+static struct stream *stream_create(struct spa_bt_transport *t, struct group *group)
 {
 	struct stream *stream;
 	void *codec_data = NULL;

spa/plugins/bluez5/midi-enum.c

@@ -202,7 +202,7 @@ static int read_probe(struct impl *impl, MidiEnumCharacteristicProxy *chr)
 	return 0;
 }
 
-Bluez5GattDescriptor1 *find_dsc(struct impl *impl, MidiEnumCharacteristicProxy *chr)
+static Bluez5GattDescriptor1 *find_dsc(struct impl *impl, MidiEnumCharacteristicProxy *chr)
 {
 	const char *path = g_dbus_proxy_get_object_path(G_DBUS_PROXY(chr));
 	Bluez5GattDescriptor1 *found = NULL;;

spa/plugins/support/cpu.c

@@ -39,7 +39,7 @@ struct impl {
 	uint32_t vm_type;
 };
 
-char *spa_cpu_read_file(const char *name, char *buffer, size_t len)
+static char *spa_cpu_read_file(const char *name, char *buffer, size_t len)
 {
 	int n, fd;