scripts/check_format: check trailing whitespace

Fix up the two existing instances of trailing whitespace in text files,
and add a check to enforce that no new trailing whitespace is added.

Change-Id: I2197bed69bb356142aa6d2e4e8261c7434dd358b
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/383291
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

scripts/eofnl

@@ -29,4 +29,10 @@ if grep -q $'\r' "$f"; then
 	exit 1
 fi
 
+if grep -q $'[\t ]$' "$f"; then
+	echo "$f: Trailing whitespace"
+	sed -i $'s/[ \t]*$//' "$f"
+	exit 1
+fi
+
 exit 0