better way to check for empty strings

Change-Id: Ib52b3f958e9e346194d4427bf59c6f62ee8ed105
Signed-off-by: Michael Stahl <mstahl@redhat.com>

sal/osl/w32/profile.cxx

@@ -2389,7 +2389,7 @@ static sal_Bool lookupProfile(const sal_Unicode *strPath, const sal_Unicode *str
                         osl_closeProfile(hProfile);
 
                         /* if not found, try the fallback */
-                        if ((strlen(Buffer) <= 0)
+                        if ((Buffer[0] == '\0')
                             && (strcmp(SVERSION_LOCATION, SVERSION_FALLBACK)
                                 != 0))
                         {