vat: fix vat_suspend crash

vat: fix vat_suspend crash

Deadly combination is clib_{set,long}jmp + lazy linking + tail call compiler
optimization. On the first call to clib_setjmp, dynamic linker executes loader
code which then calls clib_setjmp, so stored stack position contains dynamic
loader data. Tail call optimization simply jumps back to the calling
code when clib_longjump is called and that results in wrong return
address used from the stack.

Change-Id: Ia7d8dbd5b2c425cdd0449374aa07ab6b684a330e
Type: fix
Signed-off-by: Damjan Marion <damarion@cisco.com>