ecpg: Fix off-by-one error in memory copying

In a rare case, one byte past the end of memory belonging to the
sqlca_t structure would be written to.

found by Coverity

Author: petere

src/interfaces/ecpg/ecpglib/misc.c

@@ -530,7 +530,7 @@ ECPGset_var(int number, void *pointer, int lineno)
 		struct sqlca_t *sqlca = ECPGget_sqlca();
 
 		sqlca->sqlcode = ECPG_OUT_OF_MEMORY;
-		strncpy(sqlca->sqlstate, "YE001", sizeof("YE001"));
+		strncpy(sqlca->sqlstate, "YE001", sizeof(sqlca->sqlstate));
 		snprintf(sqlca->sqlerrm.sqlerrmc, sizeof(sqlca->sqlerrm.sqlerrmc), "out of memory on line %d", lineno);
 		sqlca->sqlerrm.sqlerrml = strlen(sqlca->sqlerrm.sqlerrmc);
 		/* free all memory we have allocated for the user */