Add more diff -b to roundtrip-compress.test

It was missing on the first test invocation. The flag is necessary to
ignore line-ending differences on Windows.

llvm/test/tools/llvm-profdata/roundtrip-compress.test

@@ -2,7 +2,7 @@ REQUIRES: zlib
 # Round trip from text --> compressed extbinary --> text
 RUN: llvm-profdata merge --sample --extbinary -compress-all-sections -output=%t.1.profdata %S/Inputs/sample-profile.proftext
 RUN: llvm-profdata merge --sample --text -output=%t.1.proftext %t.1.profdata
-RUN: diff %t.1.proftext %S/Inputs/sample-profile.proftext
+RUN: diff -b %t.1.proftext %S/Inputs/sample-profile.proftext
 # Round trip from text --> binary --> compressed extbinary --> text
 RUN: llvm-profdata merge --sample --binary -output=%t.2.profdata %S/Inputs/sample-profile.proftext
 RUN: llvm-profdata merge --sample --extbinary -compress-all-sections -output=%t.3.profdata %t.2.profdata