Ensure screenNum is always initialized

Clears this warning from clang, even though it seems like a
false positive, as all the uses are behind the same conditions:

xdriinfo.c:117:27: warning: variable 'screenNum' may be uninitialized
  when used here [-Wconditional-uninitialized]
    if (func == DRIVER && screenNum == -1) {
                          ^~~~~~~~~
xdriinfo.c:61:28: note: initialize the variable 'screenNum' to silence
  this warning
    int nScreens, screenNum;

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/xdriinfo.c b/xdriinfo.c
index 1bca9c4..35d7458 100644
--- a/xdriinfo.c
+++ b/xdriinfo.c
@@ -112,6 +112,8 @@ int main (int argc, char *argv[]) {
 	    return 1;
 	}
     }
+    else
+        screenNum = -1;
 
   /* driver command needs a valid screen number */
     if (func == DRIVER && screenNum == -1) {