exfat: fix compile warning

libexfat/compiler.h

@@ -33,6 +33,7 @@
 #define PRINTF __attribute__((format(printf, 1, 2)))
 #define NORETURN __attribute__((noreturn))
 #define PACKED __attribute__((packed))
+#undef  UNUSED
 #define UNUSED __attribute__((unused))
 #if __has_extension(c_static_assert)
 #define USE_C11_STATIC_ASSERT
@@ -43,6 +44,7 @@
 #define PRINTF __attribute__((format(printf, 1, 2)))
 #define NORETURN __attribute__((noreturn))
 #define PACKED __attribute__((packed))
+#undef  UNUSED
 #define UNUSED __attribute__((unused))
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
 #define USE_C11_STATIC_ASSERT

libexfat/exfat.h

@@ -28,7 +28,6 @@
 /* Android.bp is used instead of autotools when targeting Android */
 #include "config.h"
 #endif
-#include "compiler.h"
 #include "exfatfs.h"
 #include <stdio.h>
 #include <stdlib.h>

libexfat/lookup.c

@@ -219,4 +219,5 @@ int exfat_split(struct exfat* ef, struct exfat_node** parent,
 		*parent = *node;
 	}
 	exfat_bug("impossible");
+	return -ENOENT;
 }

libexfat/repair.c

@@ -58,6 +58,7 @@ bool exfat_ask_to_fix(const struct exfat* ef)
 		return yeah;
 	}
 	exfat_bug("invalid repair option value: %d", ef->repair);
+	return false;
 }
 
 bool exfat_fix_invalid_vbr_checksum(const struct exfat* ef, void* sector,

mkfs/mkexfat.c

@@ -159,4 +159,5 @@ off_t get_position(const struct fs_object* object)
 		position += (*pp)->get_size();
 	}
 	exfat_bug("unknown object");
+	return 0;
 }