ARM: recognize gfortran pre-releases

Without proper recognition of gfortran versions such as
> GNU Fortran (GCC) 4.9.x 20150123 (prerelease)
OpenBLAS assumes the presence of the G77 compiler. Consequently,
`-lgfortran` is missing from the pkg-config file.

The aforementioned compiler is the gfortran compiler in the Android repo
in a commit tagged as `ndk-r14`, cf. Paul Mustière's gfortran build
instructions for Android at https://github.com/buffer51/android-gfortran

f_check

@@ -71,7 +71,7 @@ if ($compiler eq "") {
 
 	if ($data =~ /GNU/) {
 
-	    $data =~ /(\d)\.(\d).(\d)/;
+	    $data =~ /(\d)\.(\d).(.)/;
 	    $major = $1;
 	    $minor = $2;