line-range.h: drop extern from function declaration

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

line-range.h

@@ -19,7 +19,7 @@
 
 typedef const char *(*nth_line_fn_t)(void *data, long lno);
 
-extern int parse_range_arg(const char *arg,
+int parse_range_arg(const char *arg,
 		    nth_line_fn_t nth_line_cb,
 		    void *cb_data, long lines, long anchor,
 		    long *begin, long *end,
@@ -34,6 +34,6 @@ extern int parse_range_arg(const char *arg,
  * NULL in case the argument is obviously malformed.
  */
 
-extern const char *skip_range_arg(const char *arg);
+const char *skip_range_arg(const char *arg);
 
 #endif /* LINE_RANGE_H */