Replace explicit use of Inj instances by inj

This was inconsistent and not explained before.

theories/namespaces.v

@@ -58,7 +58,7 @@ Section namespace.
     intros Hxy a. unfold up_close. rewrite !nclose_eq, !ndot_eq.
     unfold nclose_def, ndot_def; rewrite !elem_coPset_suffixes.
     intros [qx ->] [qy Hqy].
-    revert Hqy. by intros [= ?%encode_inj]%positives_flatten_suffix_eq.
+    revert Hqy. by intros [= ?%(inj _)]%positives_flatten_suffix_eq.
   Qed.
 
   Lemma ndot_preserve_disjoint_l N E x : ↑N ## E → ↑N.@x ## E.

theories/option.v

@@ -189,8 +189,8 @@ Lemma fmap_Some_equiv {A B} `{Equiv B} `{!Equivalence (≡@{B})} (f : A → B) m
   f <$> mx ≡ Some y ↔ ∃ x, mx = Some x ∧ y ≡ f x.
 Proof.
   destruct mx; simpl; split.
-  - intros ?%Some_equiv_inj. eauto.
-  - intros (? & ->%Some_inj & ?). constructor. done.
+  - intros ?%(inj _). eauto.
+  - intros (? & ->%(inj _) & ?). constructor. done.
   - intros ?%symmetry%equiv_None. done.
   - intros (? & ? & ?). done.
 Qed.