[test] Use yaml2obj -o %t instead of > %t
To improve consistency and avoid unneeded shell feature (output
redirection).
While here, make other changes to improve consistency
--docnum 1 => --docnum=1
-docnum=x => --docnum=x
diff --git a/llvm/test/tools/llvm-objcopy/ELF/prefix-alloc-sections.test b/llvm/test/tools/llvm-objcopy/ELF/prefix-alloc-sections.test
index 4cb9df5..731c332 100644
--- a/llvm/test/tools/llvm-objcopy/ELF/prefix-alloc-sections.test
+++ b/llvm/test/tools/llvm-objcopy/ELF/prefix-alloc-sections.test
@@ -1,4 +1,4 @@
-# RUN: yaml2obj %s > %t
+# RUN: yaml2obj %s -o %t
# RUN: llvm-objcopy --prefix-alloc-sections=.prefix %t %t2
# RUN: llvm-readobj --sections %t2 | FileCheck %s