use auto type when assigning from cast or using new

src/fix_deposit.cpp

@@ -844,7 +844,7 @@ void FixDeposit::write_restart(FILE *fp)
 void FixDeposit::restart(char *buf)
 {
   int n = 0;
-  double *list = (double *) buf;
+  auto list = (double *) buf;
 
   seed = static_cast<int>(list[n++]);
   ninserted = static_cast<int>(list[n++]);