patch 9.1.0997: too many strlen() calls in drawscreen.c

Problem:  too many strlen() calls in drawscreen.c
Solution: refactor drawscreen.c and remove calls to strlen(),
          make get_keymap_str() (in screen.c) return string length
          instead of TRUE/FALSE (John Marriott).

Signed-off-by: John Marriott <basilisk@internode.on.net>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/buffer.pro b/src/proto/buffer.pro
index dc68ca8..5491940 100644
--- a/src/proto/buffer.pro
+++ b/src/proto/buffer.pro
@@ -44,12 +44,12 @@
 int otherfile(char_u *ffname);
 void buf_setino(buf_T *buf);
 void fileinfo(int fullname, int shorthelp, int dont_truncate);
-void col_print(char_u *buf, size_t buflen, int col, int vcol);
+int col_print(char_u *buf, size_t buflen, int col, int vcol);
 void maketitle(void);
 void resettitle(void);
 void free_titles(void);
 int build_stl_str_hl(win_T *wp, char_u *out, size_t outlen, char_u *fmt, char_u *opt_name, int opt_scope, int fillchar, int maxwidth, stl_hlrec_T **hltab, stl_hlrec_T **tabtab);
-void get_rel_pos(win_T *wp, char_u *buf, int buflen);
+int get_rel_pos(win_T *wp, char_u *buf, int buflen);
 char_u *fix_fname(char_u *fname);
 void fname_expand(buf_T *buf, char_u **ffname, char_u **sfname);
 void ex_buffer_all(exarg_T *eap);