[atomics.ref.float] Fix indentation (#9016)

Author: Andreas-Krug

source/threads.tex

@@ -3988,7 +3988,7 @@
 \indexlibrarymember{fetch_min}{atomic_ref<\placeholder{floating-point-type}>}%
 \begin{itemdecl}
 constexpr value_type fetch_@\placeholdernc{key}@(value_type operand,
-                          memory_order order = memory_order::seq_cst) const noexcept;
+                               memory_order order = memory_order::seq_cst) const noexcept;
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -4067,7 +4067,7 @@
 \indexlibrarymember{store_fmaximum_num}{atomic_ref<\placeholder{floating-point-type}>}%
 \begin{itemdecl}
 constexpr void store_@\placeholdernc{key}@(value_type operand,
-                          memory_order order = memory_order::seq_cst) const noexcept;
+                         memory_order order = memory_order::seq_cst) const noexcept;
 \end{itemdecl}
 
 \begin{itemdescr}