Typo in morphisms.tex

Thanks to Dario Weissmann
https://stacks.math.columbia.edu/tag/0476#comment-3221

morphisms.tex

@@ -7804,7 +7804,7 @@ \section{\'Etale morphisms}
 \medskip\noindent
 In case (2) let $x' \in W'$. Then $g'$ is flat at $x'$
 (Lemma \ref{lemma-base-change-module-flat}) and
-$g \circ f$ is flat at $x'$ (Lemma \ref{lemma-composition-module-flat}).
+$g \circ f'$ is flat at $x'$ (Lemma \ref{lemma-composition-module-flat}).
 It follows that $f$ is flat at $x = g'(x')$
 by Lemma \ref{lemma-flat-permanence}. On the other hand, since
 $x' \in T'$ (Lemma \ref{lemma-base-change-smooth})