configure: Earlier pkg-config probe

Probe pkg-config before it is used for the first time (libseccomp check).
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

configure

@@ -1359,6 +1359,14 @@ esac
 
 fi
 
+##########################################
+# pkg-config probe
+
+if ! has "$pkg_config_exe"; then
+  echo "Error: pkg-config binary '$pkg_config_exe' not found"
+  exit 1
+fi
+
 ##########################################
 # NPTL probe
 
@@ -1589,14 +1597,6 @@ if test "$xen_pci_passthrough" != "no"; then
   fi
 fi
 
-##########################################
-# pkg-config probe
-
-if ! has "$pkg_config_exe"; then
-  echo "Error: pkg-config binary '$pkg_config_exe' not found"
-  exit 1
-fi
-
 ##########################################
 # libtool probe