Fix unintitialised TIC6X data

Fix unintitialised TIC6X data

MALLOC_PERTURB_=1 results in the following fails due to uninitialised
exindx data:

FAIL: C6X unwinding directives 1 (little endian)
FAIL: C6X unwinding directives 2 (big endian)
FAIL: C6X unwinding directives 3 (segment change)
FAIL: ld-tic6x/unwind-1
FAIL: ld-tic6x/unwind-2
FAIL: ld-tic6x/unwind-3
FAIL: ld-tic6x/unwind-4
FAIL: ld-tic6x/unwind-6

	* config/tc-tic6x.c (s_tic6x_ehtype): Clear after frag_more.
	(tic6x_output_exidx_entry): Likewise.
	(md_apply_fix): Simplify 1 byte md_number_to_chars.