Prevent the pre-computation of log10(new_npets-1) in optimized mode

by making new_npets volatile. This way, even when user specifies
trapping on all FPEs, there isn't an issue, even for new_npets==1.
This is solution leads to cleaner code than the initial work-around
solution committed under hash 1fd5b0.

Author: theurich

src/Infrastructure/VM/src/ESMCI_VMKernel.C

@@ -1874,7 +1874,9 @@ void *VMK::startup(class VMKPlan *vmp, void *(fctp)(void *, void *),
 #endif
   // next, determine new_npets and new_mypet_base ...
   int new_mypet_base=0;
-  int new_npets=0;
+  volatile int new_npets=0;   // volatile to prevent precompute of log10() below
+                              // in optimized mode or else might trigger SIGFPE
+                              // for new_npets==1 if user code sets FPE trapping
   int found_my_pet_flag = 0;
   for (int ii=0; ii<npets; ii++){
     int i = vmp->petlist[ii];   // indirection to preserve petlist order