changes.src: fix old typo

arror -> error

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/doc/changes.src b/doc/changes.src
index 26c43b3..b0768c9 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -48,7 +48,7 @@
 \b Allow 64-bit outputs in 16/32-bit only backends.  Unsigned 64-bit
    relocations are zero-extended from 32-bits with a warning
    (suppressible via \c{-w-zext-reloc}); signed 64-bit relocations are
-   an arror.
+   an error.
 
 \b Line numbers in list files now correspond to the lines in the source
    files, instead of simply being sequential.