flash/startup: make program accept filenames with spaces and other characters

This should allow to process any path names excluding those that have
curly braces.

Change-Id: I87bf9ddede11e2b28d5826878eb1338143f73c03
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/4083
Tested-by: jenkins

src/flash/startup.tcl

@@ -42,6 +42,7 @@ proc program {filename args} {
 
 	# start programming phase
 	echo "** Programming Started **"
+	set filename \{$filename\}
 	if {[info exists address]} {
 		set flash_args "$filename $address"
 	} else {