Addition to BUG#36573 - myisampack --join does not create destination table

                      .frm file
      
Added FLUSH TABLES before myisampack --join operation to fix the test 
warnings or errors
Removed unused variable in create_dest_frm() method

mysql-test/r/myisampack.result

@@ -91,12 +91,14 @@ CREATE TABLE t1(a INT);
 INSERT INTO t1 VALUES(20);
 CREATE TABLE t2(a INT);
 INSERT INTO t2 VALUES(40);
+FLUSH TABLE t1,t2;
 #If the myisampack --join operation is successful, we have table t3(.frm)
 #so we should be able to query about the table from server.
 SELECT COUNT(a) FROM t3;
 COUNT(a)
 1024
 # ===== myisampack.2 =====
+FLUSH TABLE t3;
 #Tests the myisampack join operation with an existing destination .frm file, 
 #the command should return correct exit status(0) and
 #we should be able to query the table.

mysql-test/t/myisampack.test

@@ -124,7 +124,7 @@ let $i=9;
 --disable_query_log
 while ($i)
 {
- INSERT INTO t1 SELECT  ROUND(a * RAND() * 10) from t1;
+ INSERT INTO t1 SELECT a from t1;
  dec $i;
 }
 --enable_query_log
@@ -136,11 +136,12 @@ let $i=9;
 --disable_query_log
 while ($i)
 {
- INSERT INTO t2 SELECT  ROUND(a * RAND() * 10) from t2;
+ INSERT INTO t2 SELECT a from t2;
  dec $i;
 }
 --enable_query_log
 
+FLUSH TABLE t1,t2;
 --exec $MYISAMPACK --join=$MYSQLD_DATADIR/test/t3 $MYSQLD_DATADIR/test/t1 $MYSQLD_DATADIR/test/t2 2>&1
 
 --echo #If the myisampack --join operation is successful, we have table t3(.frm)
@@ -153,6 +154,7 @@ SELECT COUNT(a) FROM t3;
 # It should finish the join operation successfully
 #############################################################################
 --echo # ===== myisampack.2 =====
+FLUSH TABLE t3;
 --remove_file $MYSQLD_DATADIR/test/t3.MYI
 --remove_file $MYSQLD_DATADIR/test/t3.MYD
 --exec $MYISAMPACK --join=$MYSQLD_DATADIR/test/t3 $MYSQLD_DATADIR/test/t1 $MYSQLD_DATADIR/test/t2 2>&1

storage/myisam/myisampack.c

@@ -781,7 +781,6 @@ static int compress(PACK_MRG_INFO *mrg,char *result_table)
 static int create_dest_frm(char *source_table, char *dest_table)
 {
   char source_name[FN_REFLEN], dest_name[FN_REFLEN];
-  int error;
   
   DBUG_ENTER("create_dest_frm");