Remove stale inline function handling from selftest_setup

Remove stale inline function handling from selftest_setup

Before commit 70ee000084aa ("[gdb] Allow function arguments in bp
print match in selftest_setup"), this pattern in selftest_setup:

	-re "Starting program.*Breakpoint \[0-9\]+,.* at .*main.c:.*$function.*$gdb_prompt $" {
	    # $function may be inlined, so the program stops at the line
	    # calling $function.
	    pass "$description"
	}

happened to match if captured_main_1 was inlined and captured_main was
not, because captured_main calls captured_main_1 first thing, which
coincidentally matches "$function.*":

 Breakpoint 1, captured_main (data=<optimized out>) at src/gdb/main.c:1147
 1147      captured_main_1 (context);

That would probably be better "$function .*", with a space, but I
think that even better is to remove the "may be inlined" case too now,
because since ddfe970e6bec ("Don't elide all inlined frames") GDB
presents the stop at the inline function instead of at the caller.

gdb/testsuite/ChangeLog:
2018-06-14  Pedro Alves  <palves@redhat.com>

	* lib/selftest-support.exp (selftest_setup): Remove inlined
	function handling.