Remove blank line before the end of some structs

src/posix_thread.h

@@ -37,7 +37,6 @@ typedef struct _GLFWtlsPOSIX
 {
     GLFWbool        allocated;
     pthread_key_t   key;
-
 } _GLFWtlsPOSIX;
 
 // POSIX-specific mutex data
@@ -46,6 +45,5 @@ typedef struct _GLFWmutexPOSIX
 {
     GLFWbool        allocated;
     pthread_mutex_t handle;
-
 } _GLFWmutexPOSIX;