Replace "|&" with "2>&1 |" to support bash pre-4

Summary: Old bash release (3.2) on SLES11 chokes on new redirection shortcut.

Patch by Brian Cain.

Reviewers: eugenis

Subscribers: llvm-commits, kubabrecka

Differential Revision: https://reviews.llvm.org/D27443

llvm-svn: 288854