[WP] fixes a typo in a test.

src/plugins/wp/tests/wp_acsl/oracle_qualif/issue_A228.res.oracle

 # frama-c -wp [...]
 [kernel] Parsing tests/wp_acsl/issue_A228.c (with preprocessing)
-[kernel] :0: 
-  syntax error:
-  Location: between <unknown> and 1:5, before or at token: A
-  
-  1     Bool A, B;
-  
-  2     
-  3     /*@
-[kernel] Frama-C aborted: invalid user input.
+[wp] Running WP plugin...
+[wp] Warning: Missing RTE guards
+[wp] 1 goal scheduled
+[wp] [Alt-Ergo] Goal typed_job_ensures_GOAL : Timeout (Qed:4ms) (10s) (missing cache)
+[wp] Proved goals:    0 / 1
+  Alt-Ergo:        0  (unsuccess: 1)
+------------------------------------------------------------
+ Functions                 WP     Alt-Ergo  Total   Success
+  job                       -        -        1       0.0%
+------------------------------------------------------------