xkb: initialize tsyms

This fixes some “Conditional jump depends on uninitialized value(s)”
errors spotted by valgrind.

Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>

xkb/xkbUtils.c

@@ -222,7 +222,7 @@ XkbUpdateKeyTypesFromCore(DeviceIntPtr pXDev,
     XkbDescPtr xkb;
     unsigned key, nG, explicit;
     int types[XkbNumKbdGroups];
-    KeySym tsyms[XkbMaxSymsPerKey], *syms;
+    KeySym tsyms[XkbMaxSymsPerKey] = {NoSymbol}, *syms;
     XkbMapChangesPtr mc;
 
     xkb = pXDev->key->xkbInfo->desc;