check scripts: handle unintialized driver vars in check-driverimpls.pl

Current script confuses on lines like this:

static virHypervisorDriver parallelsHypervisorDriver;

It interprets next lines as if there is open brace.

Let's filter this case from matches.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/check-driverimpls.pl

@@ -67,7 +67,7 @@ while (<>) {
                 $status = 1;
             }
         }
-    } elsif (/^(?:static\s+)?(vir(?:\w+)?Driver)\s+/) {
+    } elsif (/^(?:static\s+)?(vir(?:\w+)?Driver)\s+(?!.*;)/) {
         next if $1 eq "virNWFilterCallbackDriver" ||
                 $1 eq "virNWFilterTechDriver" ||
                 $1 eq "virConnectDriver";