libfdt: Trivial cleanup for CHECK_HEADER)

Currently the CHECK_HEADER() macro is defined local to fdt_ro.c.
However, there are a handful of functions (fdt_move, rw_check_header,
fdt_open_into) from other files which could also use it (currently
they open-code something more-or-less identical).  Therefore, this
patch moves CHECK_HEADER() to libfdt_internal.h and uses it in those
places.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

libfdt/fdt.c

@@ -184,10 +184,7 @@ const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
 
 int fdt_move(const void *fdt, void *buf, int bufsize)
 {
-	int err = fdt_check_header(fdt);
-
-	if (err)
-		return err;
+	CHECK_HEADER(fdt);
 
 	if (fdt_totalsize(fdt) > bufsize)
 		return -FDT_ERR_NOSPACE;

libfdt/fdt_ro.c

@@ -55,13 +55,6 @@
 
 #include "libfdt_internal.h"
 
-#define CHECK_HEADER(fdt) \
-	{ \
-		int err; \
-		if ((err = fdt_check_header(fdt)) != 0) \
-			return err; \
-	}
-
 static int nodename_eq(const void *fdt, int offset,
 		       const char *s, int len)
 {

libfdt/fdt_rw.c

@@ -69,10 +69,8 @@ static int _blocks_misordered(const void *fdt,
 
 static int rw_check_header(void *fdt)
 {
-	int err;
+	CHECK_HEADER(fdt);
 
-	if ((err = fdt_check_header(fdt)))
-		return err;
 	if (fdt_version(fdt) < 17)
 		return -FDT_ERR_BADVERSION;
 	if (_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
@@ -399,9 +397,7 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
 	int newsize;
 	void *tmp;
 
-	err = fdt_check_header(fdt);
-	if (err)
-		return err;
+	CHECK_HEADER(fdt);
 
 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 		* sizeof(struct fdt_reserve_entry);

libfdt/libfdt_internal.h

@@ -58,6 +58,13 @@
 #define memeq(p, q, n)	(memcmp((p), (q), (n)) == 0)
 #define streq(p, q)	(strcmp((p), (q)) == 0)
 
+#define CHECK_HEADER(fdt) \
+	{ \
+		int err; \
+		if ((err = fdt_check_header(fdt)) != 0) \
+			return err; \
+	}
+
 uint32_t _fdt_next_tag(const void *fdt, int startoffset, int *nextoffset);
 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s);
 int _fdt_node_end_offset(void *fdt, int nodeoffset);