[diff.cpp17.depr] Fix typo from P0619R4 (#2217)

In the paper, "raw_memory_iterator" was meant to say "raw_storage_iterator".

Author: cubbimew

source/compatibility.tex

@@ -2073,7 +2073,7 @@
 \tcode{allocate} with an additional hint argument, may fail to compile.
 
 \nodiffref
-\change Remove \tcode{raw_memory_iterator}.
+\change Remove \tcode{raw_storage_iterator}.
 \rationale
 The iterator encouraged use of algorithms that might throw exceptions, but did
 not return the number of elements successfully constructed that might need to