fix ARM --with-fpu option checking and error message

fix ARM --with-fpu option checking and error message

Fix the test for failure in parsecpu's checking of the --with-fpu
argument, and the error message that gets printed when the check
fails.

for  gcc/ChangeLog

	* config.gcc: Fix ARM --with-fpu checking and error message.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@272496 138bc75d-0d04-0410-961f-82ee72b054a4