whitespace: have SP on both sides of an assignment "="

I've deliberately excluded the borrowed code in compat/nedmalloc
directory.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/read-cache.c b/read-cache.c
index 4ac9a03..0a64103 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1087,7 +1087,7 @@
 {
 	if (in_porcelain && *first && header_msg) {
 		printf("%s\n", header_msg);
-		*first=0;
+		*first = 0;
 	}
 	printf(fmt, name);
 }