MAKEALL: Do a sanity check on user-supplied arguments

Add a check to make sure that the user's arguments actually find a board
in boards.cfg.  Previously, if a user misspelled an argument the
argument would be discarded without warning.  For example, running
'MAKEALL -c 85xx' with the intention of compiling all Freescale 85xx
boards would instead silently discard the '-c 85xx' argument since the
proper cpu name is 'mpc85xx' and then proceed to compile all PowerPC
boards (MAKEALL's default).

Also fix an unrelated typo.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>

MAKEALL

@@ -11,7 +11,7 @@
 # line; without any arguments, MAKEALL defaults to building all Power
 # Architecture systems (i. e. same as for "MAKEALL powerpc").
 #
-# With the iontroduction of the board.cfg file, it has become possible
+# With the introduction of the board.cfg file, it has become possible
 # to provide additional selections.  We use standard command line
 # options for this:
 #
@@ -125,6 +125,12 @@ FILTER="\$1 !~ /^#/"
 
 if [ "$SELECTED" ] ; then
 	SELECTED=$(awk '('"$FILTER"') { print $1 }' boards.cfg)
+
+	# Make sure some boards from boards.cfg are actually found
+	if [ -z "$SELECTED" ] ; then
+		echo "Error: No boards selected, invalid arguments"
+		exit 1
+	fi
 fi
 
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