lib/bitmap.c: correct a code style and do some, optimization

We can avoid in-loop incrementation of ndigits.  Save current totaldigits
to ndigits before loop, and check ndigits against totaldigits after the
loop.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/bitmap.c

@@ -367,7 +367,8 @@ int __bitmap_parse(const char *buf, unsigned int buflen,
 
 	nchunks = nbits = totaldigits = c = 0;
 	do {
-		chunk = ndigits = 0;
+		chunk = 0;
+		ndigits = totaldigits;
 
 		/* Get the next chunk of the bitmap */
 		while (buflen) {
@@ -406,9 +407,9 @@ int __bitmap_parse(const char *buf, unsigned int buflen,
 				return -EOVERFLOW;
 
 			chunk = (chunk << 4) | hex_to_bin(c);
-			ndigits++; totaldigits++;
+			totaldigits++;
 		}
-		if (ndigits == 0)
+		if (ndigits == totaldigits)
 			return -EINVAL;
 		if (nchunks == 0 && chunk == 0)
 			continue;