reflog: fix cast warning

/home/kas/git/public/libgit2/src/reflog.c: In function ‘reflog_parse’:
/home/kas/git/public/libgit2/src/reflog.c:148:17: warning: cast discards ‘__attribute__((const))’ qualifier from pointer target type [-Wcast-qual]

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

src/reflog.c

@@ -145,12 +145,12 @@ static int reflog_parse(git_reflog *log, const char *buf, size_t buf_size)
 		if (*buf == '\t') {
 			/* We got a message. Read everything till we reach LF. */
 			seek_forward(1);
-			entry->msg = (char *)buf;
+			ptr = buf;
 
 			while (*buf && *buf != '\n')
 				seek_forward(1);
 
-			entry->msg = git__strndup(entry->msg, buf - entry->msg);
+			entry->msg = git__strndup(ptr, buf - ptr);
 		} else
 			entry->msg = NULL;