bootstrap: Fix patching warnings

bootstrap: Fix patching warnings

Currently bootstrap complains in the following way when
patching gnulib files:

  patching file argp-help.c
  Hunk #1 succeeded at 52 (offset 1 line).
  Hunk #2 succeeded at 1548 (offset 115 lines).
  patching file mbswidth.c
  patching file mbswidth.h
  Hunk #1 succeeded at 40 (offset -5 lines).

Let's fix it by amending line numbers in the patch.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>