Fix final compiler warning produced by -Wshadow=compatible-local

We're now able to compile the entire tree with -Wshadow=compatible-local
without any compiler warnings.

Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvqWGMdB_pATeUqE=JCtNqNxObPOJ00jFEa2_sZ20j_Wvg@mail.gmail.com

src/bin/pgbench/pgbench.c

@@ -7506,9 +7506,9 @@ threadRun(void *arg)
 		/* progress report is made by thread 0 for all threads */
 		if (progress && thread->tid == 0)
 		{
-			pg_time_usec_t now = pg_time_now();
+			pg_time_usec_t now2 = pg_time_now();
 
-			if (now >= next_report)
+			if (now2 >= next_report)
 			{
 				/*
 				 * Horrible hack: this relies on the thread pointer we are
@@ -7516,7 +7516,7 @@ threadRun(void *arg)
 				 * entry of the threads array.  That is why this MUST be done
 				 * by thread 0 and not any other.
 				 */
-				printProgressReport(thread, thread_start, now,
+				printProgressReport(thread, thread_start, now2,
 									&last, &last_report);
 
 				/*
@@ -7526,7 +7526,7 @@ threadRun(void *arg)
 				do
 				{
 					next_report += (int64) 1000000 * progress;
-				} while (now >= next_report);
+				} while (now2 >= next_report);
 			}
 		}
 	}