Declare local functions as static

PR #4374 <https://github.com/Genymobile/scrcpy/pull/4374>

Co-authored-by: Romain Vimont <rom@rom1v.com>
Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/adb/adb_parser.c

@@ -7,7 +7,7 @@
 #include "util/log.h"
 #include "util/str.h"
 
-bool
+static bool
 sc_adb_parse_device(char *line, struct sc_adb_device *device) {
     // One device line looks like:
     // "0123456789abcdef	device usb:2-1 product:MyProduct model:MyModel "

app/src/main.c

@@ -23,7 +23,7 @@
 #include "util/str.h"
 #endif
 
-int
+static int
 main_scrcpy(int argc, char *argv[]) {
 #ifdef _WIN32
     // disable buffering, we want logs immediately

app/src/scrcpy.c

@@ -90,7 +90,7 @@ push_event(uint32_t type, const char *name) {
 #define PUSH_EVENT(TYPE) push_event(TYPE, # TYPE)
 
 #ifdef _WIN32
-BOOL WINAPI windows_ctrl_handler(DWORD ctrl_type) {
+static BOOL WINAPI windows_ctrl_handler(DWORD ctrl_type) {
     if (ctrl_type == CTRL_C_EVENT) {
         PUSH_EVENT(SDL_QUIT);
         return TRUE;