[llvm-exegesis] Newline added in testfile

Author: lakshayk-nv

llvm/test/tools/llvm-exegesis/AArch64/debug-gen-asm.s

@@ -9,4 +9,4 @@ PREVIEW-NEXT: {{[48]}}: {{.*}}      addv    h{{[0-9]+}}, v{{[0-9]+}}.4h
 PREVIEW:      ...      ({{[0-9]+}} more instructions)
 PREVIEW-NEXT: {{.*}}   addv    h{{[0-9]+}}, v{{[0-9]+}}.4h
 PREVIEW:      {{.*}}   ret
-PREVIEW-NEXT:```
+PREVIEW-NEXT:```