sha1_file: fix definition of null_sha1

The array is declared in cache.h as:

  extern const unsigned char null_sha1[GIT_MAX_RAWSZ];

Definition in sha1_file.c must match.

Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: dreamer

sha1_file.c

@@ -32,7 +32,7 @@
 #define SZ_FMT PRIuMAX
 static inline uintmax_t sz_fmt(size_t s) { return s; }
 
-const unsigned char null_sha1[20];
+const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
 const struct object_id empty_tree_oid = {
 	EMPTY_TREE_SHA1_BIN_LITERAL