hash: fix "-Wsign-compare" warnings

There are a couple of trivial "-Wsign-compare" warnings in "hash.c". Fix
them.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

hash.c

@@ -1,5 +1,4 @@
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "git-compat-util.h"
 #include "hash.h"
@@ -246,28 +245,25 @@ const char *empty_tree_oid_hex(const struct git_hash_algo *algop)
 
 int hash_algo_by_name(const char *name)
 {
-	int i;
 	if (!name)
 		return GIT_HASH_UNKNOWN;
-	for (i = 1; i < GIT_HASH_NALGOS; i++)
+	for (size_t i = 1; i < GIT_HASH_NALGOS; i++)
 		if (!strcmp(name, hash_algos[i].name))
 			return i;
 	return GIT_HASH_UNKNOWN;
 }
 
 int hash_algo_by_id(uint32_t format_id)
 {
-	int i;
-	for (i = 1; i < GIT_HASH_NALGOS; i++)
+	for (size_t i = 1; i < GIT_HASH_NALGOS; i++)
 		if (format_id == hash_algos[i].format_id)
 			return i;
 	return GIT_HASH_UNKNOWN;
 }
 
-int hash_algo_by_length(int len)
+int hash_algo_by_length(size_t len)
 {
-	int i;
-	for (i = 1; i < GIT_HASH_NALGOS; i++)
+	for (size_t i = 1; i < GIT_HASH_NALGOS; i++)
 		if (len == hash_algos[i].rawsz)
 			return i;
 	return GIT_HASH_UNKNOWN;

hash.h

@@ -325,7 +325,7 @@ int hash_algo_by_name(const char *name);
 /* Identical, except based on the format ID. */
 int hash_algo_by_id(uint32_t format_id);
 /* Identical, except based on the length. */
-int hash_algo_by_length(int len);
+int hash_algo_by_length(size_t len);
 /* Identical, except for a pointer to struct git_hash_algo. */
 static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
 {