util: Follow up to r1897101 and r1897105: Yet better ap_cstr_casecmp[n]().

util: Follow up to r1897101 and r1897105: Yet better ap_cstr_casecmp[n]().

Now with a shorter epilogue.

Dump of assembler code for function ap_cstr_casecmp:
   0x0000000000049fd0 <+0>:	xor    %edx,%edx
   0x0000000000049fd2 <+2>:	lea    0x3d567(%rip),%r8        # 0x87540 <ucharmap>
   0x0000000000049fd9 <+9>:	nopl   0x0(%rax)
   0x0000000000049fe0 <+16>:	movzbl (%rsi,%rdx,1),%eax
   0x0000000000049fe4 <+20>:	movzbl (%r8,%rax,1),%ecx
   0x0000000000049fe9 <+25>:	movzbl (%rdi,%rdx,1),%eax
   0x0000000000049fed <+29>:	add    $0x1,%rdx
   0x0000000000049ff1 <+33>:	movzbl (%r8,%rax,1),%eax
   0x0000000000049ff6 <+38>:	sub    %ecx,%eax
   0x0000000000049ff8 <+40>:	jne    0x49ffe <ap_cstr_casecmp+46>
   0x0000000000049ffa <+42>:	test   %ecx,%ecx
   0x0000000000049ffc <+44>:	jne    0x49fe0 <ap_cstr_casecmp+16>
   0x0000000000049ffe <+46>:	ret
End of assembler dump.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1897106 13f79535-47bb-0310-9956-ffa450edef68