test(unit): Fix warning in unit test script

Eliminated error/warning message if attempt to delete .gcov
files fails when there are none to delete.

Change-Id: Ib552c3e73161ca5572d220f03498aba878a3bfc8
Signed-off-by: E. Scott Daniels <daniels@research.att.com>
diff --git a/test/unit_test.ksh b/test/unit_test.ksh
index 929976c..9953733 100755
--- a/test/unit_test.ksh
+++ b/test/unit_test.ksh
@@ -353,7 +353,7 @@
 		-x)	gen_xml=1
 			force_discounting=1
 			trigger_discount_str="WARN|FAIL|PASS"		# check all outcomes for each module
-			rm *cov.xml
+			rm -fr *cov.xml
 			;;
 
 		-h) 	usage; exit 0;;
@@ -397,7 +397,7 @@
 fi
 
 
-rm *.gcov			# ditch the previous coverage files
+rm -fr *.gcov			# ditch the previous coverage files
 ut_errors=0			# unit test errors (not coverage errors)
 errors=0