libuwac/input: Fix memory leak

`create_pointer_buffer()` allocates memory with `mmap` and never frees it.

Adding a corresponding `munmap` fixes this issue.

uwac/libuwac/uwac-input.c

@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <errno.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/mman.h>
@@ -69,6 +70,10 @@ static struct wl_buffer* create_pointer_buffer(UwacSeat* seat, const void* src,
 	                              seat->pointer_image->width * 4, WL_SHM_FORMAT_ARGB8888);
 	wl_shm_pool_destroy(pool);
 
+	if (munmap(data, size) < 0)
+		fprintf(stderr, "%s: munmap(%p, %" PRIuz ") failed with [%d] %s\n", __FUNCTION__, data,
+		        size, errno, strerror(errno));
+
 error_mmap:
 	close(fd);
 	return buffer;