Fixes for ifort 2018

1. the already deprecated -openmp option was removed in 2018, switch to -fopenmp
2. add leading blank in search for "zho_ge__" symbol to work around misleading tags in the 2018 assembly
Expected to fix #1548

f_check

@@ -97,7 +97,7 @@ if ($compiler eq "") {
 
 	if ($data =~ /Intel/) {
 	    $vendor = INTEL;
-	    $openmp = "-openmp";
+	    $openmp = "-fopenmp";
 	}
 
         if ($data =~ /Sun Fortran/) {
@@ -127,7 +127,7 @@ if ($compiler eq "") {
 
 	# for embeded underscore name, e.g. zho_ge, it may append 2 underscores.
 	$data = `$compiler -O2 -S ftest3.f > /dev/null 2>&1 && cat ftest3.s && rm -f ftest3.s`;
-	if ($data =~ /zho_ge__/) {
+	if ($data =~ / zho_ge__/) {
 	    $need2bu       = 1;
 	}
     }
@@ -155,7 +155,7 @@ if ($compiler eq "") {
 	if ($compiler =~ /ifort/) {
 	    $vendor = INTEL;
 	    $bu       = "_";
-	    $openmp = "-openmp";
+	    $openmp = "-fopenmp";
 	}
 
 	if ($compiler =~ /pathf/) {