[atomics.ref.int, atomics.ref.float] Minor \tcode fixes (#7499)

Author: Andreas-Krug

source/threads.tex

@@ -3615,7 +3615,7 @@
 \pnum
 The program is ill-formed
 if \tcode{is_always_lock_free} is \tcode{false} and
-\tcode{is_volatile_v<T>} is true.
+\tcode{is_volatile_v<T>} is \tcode{true}.
 
 \begin{codeblock}
 namespace std {
@@ -3774,7 +3774,7 @@
 
 \pnum
 The program is ill-formed
-\tcode{if is_always_lock_free} is \tcode{false} and
+if \tcode{is_always_lock_free} is \tcode{false} and
 \tcode{is_volatile_v<T>} is \tcode{true}.
 
 \begin{codeblock}