Due to raising the minimum binutils version to version >=2.28,
the used cfi_escape for cfi_val_offset can now be ommitted.
The commit 0fc76d8762
has already adjusted it for the 64bit part of mcount.
This patch also adjusts it for the 31bit part of mcount.
Checked with "objdump -WF" / "objdump -Wf" that the previous
cfi_escape and the new cfi_val_offset are equal.