mergetools: vimdiff: silence annoying messages

When using the single window mode we are greeted with the following
warning:

  "./content_LOCAL_8975" 6L, 28B
  "./content_BASE_8975" 6 lines, 29 bytes
  "./content_REMOTE_8975" 6 lines, 29 bytes
  "content" 16 lines, 115 bytes
  Press ENTER or type command to continue

every time.

Silence that.

Suggested-by: Fernando Ramos <[email protected]>
Signed-off-by: Felipe Contreras <[email protected]>
Reviewed-by: Fernando Ramos <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: felipec

mergetools/vimdiff

@@ -343,7 +343,7 @@ gen_cmd () {
 	then
 		CMD="$CMD | tabdo windo diffthis"
 	else
-		CMD="$CMD | bufdo diffthis"
+		CMD="$CMD | silent bufdo diffthis"
 	fi
 
 
@@ -558,7 +558,7 @@ run_unit_tests () {
 	EXPECTED_CMD_01="-c \"set hidden | echo | leftabove split | leftabove vertical split | 1b | wincmd l | leftabove vertical split | 2b | wincmd l | 3b | wincmd j | 4b | tabdo windo diffthis\" -c \"tabfirst\""
 	EXPECTED_CMD_02="-c \"set hidden | echo | leftabove vertical split | 1b | wincmd l | 3b | tabdo windo diffthis\" -c \"tabfirst\""
 	EXPECTED_CMD_03="-c \"set hidden | echo | leftabove vertical split | 1b | wincmd l | leftabove vertical split | 4b | wincmd l | 3b | tabdo windo diffthis\" -c \"tabfirst\""
-	EXPECTED_CMD_04="-c \"set hidden | echo | 4b | bufdo diffthis\" -c \"tabfirst\""
+	EXPECTED_CMD_04="-c \"set hidden | echo | 4b | silent bufdo diffthis\" -c \"tabfirst\""
 	EXPECTED_CMD_05="-c \"set hidden | echo | leftabove split | 1b | wincmd j | leftabove split | 4b | wincmd j | 3b | tabdo windo diffthis\" -c \"tabfirst\""
 	EXPECTED_CMD_06="-c \"set hidden | echo | leftabove vertical split | leftabove split | 1b | wincmd j | 3b | wincmd l | 4b | tabdo windo diffthis\" -c \"tabfirst\""
 	EXPECTED_CMD_07="-c \"set hidden | echo | leftabove vertical split | 4b | wincmd l | leftabove split | 1b | wincmd j | 3b | tabdo windo diffthis\" -c \"tabfirst\""