scsi: aic7xxx: Fix compiler warnings triggered by user space code

scsi: aic7xxx: Fix compiler warnings triggered by user space code

Fix the following compiler warnings:

aicasm_gram.y:1107:24: warning: comparison of different enumeration types
      ('scope_type' and 'enum yytokentype') [-Wenum-compare]
 1107 |                  || last_scope->type == T_ELSE) {
      |                     ~~~~~~~~~~~~~~~~ ^  ~~~~~~
aicasm_scan.l:392:14: warning: using the result of an assignment as a condition
      without parentheses [-Wparentheses]
  392 |                                 while (c = *yptr++) {
      |                                        ~~^~~~~~~~~
aicasm_macro_scan.l:153:1: warning: non-void function does not return a value
      [-Wreturn-type]
  153 | }
      | ^

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260402153341.2909184-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>