ptmalloc3: Fix QA issues

:Release Notes:
Pass hash-style in Makefile.palm.

:Detailed Notes:
Drop un-needed cd ${S}. Reorder variables to match OE styleguide.
Don't pass whole LDFLAGS, because doesn't work well with as-needed -
would need a bit more work.
Fixes following QA warning:
ptmalloc3-1.0: No GNU_HASH in the elf binary:
  'ptmalloc3/1.0-r1/packages-split/ptmalloc3/usr/lib/libptmalloc3.so'

:Testing Performed:
Only build tested.

:QA Notes:
No change to image.

:Issues Addressed:
[GF-42606] Ongoing metadata improvement/cleanup work
[GF-5395]  ptmalloc3 recipe doesn't pass global LDFLAGS to the linker

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: Ic38b02385006b1c86b854328b3e9d7a823f8d2a8
Reviewed-on: https://g2g.palm.com/4015
Reviewed-by: DCO Verification
Build: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>