linker: reduce size by nearly 20KB

This patch adds a trivial implementation of snprintf() that calls
our internal vsnprintf().

Inspection of the generated machine code showed that the linker
contained a full implementation of stdio's vfprintf. It was pulled
in because the pthread implementation uses snprintf() somewhere.

ProTip: It's possible to see why specific objects files are included
in a final binary by adding the following to your, then
looking at the content of /tmp/MAP.TXT:

  LOCAL_LDFLAGS += -Wl,-Map=/tmp/MAP.TXT

Change-Id: I325e71b0cad1d01116a2e00c09e30a80cb716aa3
1 file changed