When dlopen and pthread_create are in libc the variable is
set to "none required", therefore running configure will show
the following errors:

./configure: line 8997: test: too many arguments
./configure: line 8999: test: too many arguments
./configure: line 9003: test: too many arguments
./configure: line 9005: test: =: unary operator expected

ChangeLog:

	PR bootstrap/115453
	* configure.ac: Quote variable result of AC_SEARCH_LIBS.  Fix
	typo ac_cv_search_pthread_crate.
	* configure: Regenerate.

Signed-off-by: Collin Funk <collin.funk1@gmail.com>