GLIB: Configure.in looking for fd_mask instead of fd_set

["Jerry L. Kirk" <Jerry_Kirk Bigfoot com>]

I think there is a bug in configure.in (line 306-321) where configure first looks for fd_set() in sys/types and then it looks for fd_mask in sys/select.h  Under QNX fd_set is defined in sys/select.h so even this second test is failing. I am not sure if this is a simple mistake where I can just replace fd_mask with fd_set in the AC_HEADER_EGREP or maybe someone needed to look for fd_mask in sys/select.h and I should add another "else" to egrep fd_set from sys/select.h 

Simply changing fd_mask to fd_set fixes the problem for me.

	Jerry