Modify improper XFAIL checking by not running FileCheck if there are no improperly XFAIL-ed tests

Author: lbushi25

sycl/test/e2e_test_requirements/no-xfail-without-tracker.cpp

@@ -31,7 +31,7 @@
 // RUN: grep -v "XFAIL:" | \
 // RUN: grep -Pv "XFAIL-TRACKER:\s+(?:https://github.com/[\w\d-]+/[\w\d-]+/issues/[\d]+)|(?:[\w]+-[\d]+)" > %t
 // RUN: cat %t | wc -l | FileCheck %s --check-prefix NUMBER-OF-XFAIL-WITHOUT-TRACKER
-// RUN: cat %t | sed 's/\.cpp.*/.cpp/' | sort | FileCheck %s
+// RUN: cat %t | sed 's/\.cpp.*/.cpp/' | sort | wc - l | [ $(cat)  -gt 0 ] && FileCheck %s --allow-unused-prefixes
 //
 // The number below is a number of tests which are *improperly* XFAIL-ed, i.e.
 // we either don't have a tracker associated with a failure listed in those