patch crashes if non-numerical parameter for strip count

[Aapo Rantalainen]

GNU patch 2.7.1

E.g.
patch -pa

It gives correct warning
patch: **** strip count s is not a number

But then it crashes with segmentation fault:

(gdb) bt
#0 gl_list_iterator_inline (list=0x0) at ../lib/gl_list.h:762
#1 forget_output_files () at patch.c:1935
#2 cleanup () at patch.c:1978
#3 0x0000000000406a78 in fatal_exit (sig=sig@entry=0) at patch.c:1953
#4 0x000000000040c7b2 in fatal (format=format@entry=0x418162 "%s %s is not a number") at util.c:921
#5 0x0000000000405d6b in numeric_string (string=<optimized out>, negative_allowed=negative_allowed@entry=false,
    argtype_msgid=argtype_msgid@entry=0x41831f "strip count") at patch.c:1077
#6 0x00000000004028c5 in get_some_switches () at patch.c:927
#7 main (argc=<optimized out>, argv=<optimized out>) at patch.c:156