use more accurate strncmp() check instead of strstr() and apply the same change to all affected variants of fix nvt/sllod

src/fix_nvt_sllod.cpp

@@ -80,7 +80,7 @@ void FixNVTSllod::init()
 
   int i;
   for (i = 0; i < modify->nfix; i++)
-    if (strstr(modify->fix[i]->style,"deform")) {
+    if (strncmp(modify->fix[i]->style,"deform",6) == 0) {
       if (((FixDeform *) modify->fix[i])->remapflag != Domain::V_REMAP)
         error->all(FLERR,"Using fix nvt/sllod with inconsistent fix deform "
                    "remap option");