Use abort instead of panic for WITH_NO_FP

Previous commit added calls to panic()
in vf{printf,scanf}.c if floating point is disabled
(WITH_NO_FP is set). This function is only
available in the kernel. This patch replaces
it with a combination of fputs + abort which
are available in both user space and the kernel.

Bug: 230134581
Change-Id: I1020b67597b9e4403e7bd64e1924feb20e432f92
2 files changed