fix some errno related stuff, "make all" works again

libsrc/cbm/dir.s

@@ -92,8 +92,8 @@ L3:     sta     tmp1            ; Save returned count
 ; Didn't read enough bytes. This is an error for us, but errno is not set
 
         lda     #<EIO
-        sta     __errno
-        stx     __errno+1       ; X is zero
+        sta     ___errno
+        stx     ___errno+1      ; X is zero
         bne     L1              ; Branch always
 
 

libsrc/cbm/readdir.c

@@ -126,7 +126,7 @@ struct dirent* __fastcall__ readdir (register DIR* dir)
     }
 
     /* Something went wrong when parsing the directory entry */
-    _errno = EIO;
+    __errno = EIO;
 exitpoint:
     return 0;
 }