mysqltest.test: Remove output from shells in result file

mysql-test/r/mysqltest.result:
  Update test results
mysql-test/t/mysqltest.test:
  Send output from failed command to /dev/null in order to avoid recording the output from different shells

mysql-test/r/mysqltest.result

@@ -179,9 +179,7 @@ source database
 echo message echo message
 
 mysqltest: At line 1: Empty variable
-sh: -c: line 0: syntax error near unexpected token `;'
-sh: -c: line 0: `;'
-mysqltest: At line 1: command ";" failed
+mysqltest: At line 1: command "';' 2> /dev/null" failed
 mysqltest: At line 1: Missing argument in exec
 MySQL
 "MySQL"
@@ -303,8 +301,7 @@ mysqltest: At line 1: First argument to dec must be a variable (start with $)
 mysqltest: At line 1: End of line junk detected: "1000"
 mysqltest: At line 1: Missing arguments to system, nothing to do!
 mysqltest: At line 1: Missing arguments to system, nothing to do!
-sh: NonExistsinfComamdn: command not found
-mysqltest: At line 1: system command 'NonExistsinfComamdn' failed
+mysqltest: At line 1: system command 'NonExistsinfComamdn 2> /dev/null' failed
 test
 test2
 test3

mysql-test/t/mysqltest.test

@@ -424,7 +424,7 @@ echo ;
 
 # Illegal use of exec
 --error 1
---exec echo "--exec ;" | $MYSQL_TEST 2>&1
+--exec echo "--exec ';' 2> /dev/null" | $MYSQL_TEST 2>&1
 
 --error 1
 --exec echo "--exec " | $MYSQL_TEST 2>&1
@@ -672,7 +672,7 @@ system echo "hej" > /dev/null;
 --error 1
 --exec echo "system $NONEXISTSINFVAREABLI;" | $MYSQL_TEST 2>&1
 --error 1
---exec echo "system NonExistsinfComamdn;" | $MYSQL_TEST 2>&1
+--exec echo "system NonExistsinfComamdn 2> /dev/null;" | $MYSQL_TEST 2>&1
 
 --disable_abort_on_error
 system NonExistsinfComamdn;