topology: data: Fix wrong size check in tplg_parse_data_hex()

topology: data: Fix wrong size check in tplg_parse_data_hex()

A wrong, uninitialized variable is referred as the size to check in
tplg_parse_data_hex().  Spotted by gcc warning:
  data.c: In function ‘tplg_parse_data_hex’:
  data.c:228:5: warning: ‘esize’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    if (esize > TPLG_MAX_PRIV_SIZE) {
        ^
  data.c:211:12: note: ‘esize’ was declared here
    int size, esize, off, num;
              ^

Signed-off-by: Takashi Iwai <tiwai@suse.de>