math64: favor kernel-doc from header files

Fix the kernel-doc markings for div64 functions to point to the header
file instead of the lib/ directory.  This avoids having implementation
specific comments in generic documentation.  Furthermore, given that
some kernel-doc comments are identical, drop them from lib/math64 and
only keep there comments that add implementation details.

Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20221118182309.3824530-1-liambeguin@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

lib/math/div64.c

@@ -63,12 +63,6 @@ uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
 EXPORT_SYMBOL(__div64_32);
 #endif
 
-/**
- * div_s64_rem - signed 64bit divide with 64bit divisor and remainder
- * @dividend:	64bit dividend
- * @divisor:	64bit divisor
- * @remainder:  64bit remainder
- */
 #ifndef div_s64_rem
 s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 {
@@ -89,7 +83,7 @@ s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 EXPORT_SYMBOL(div_s64_rem);
 #endif
 
-/**
+/*
  * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
  * @dividend:	64bit dividend
  * @divisor:	64bit divisor
@@ -129,7 +123,7 @@ u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
 EXPORT_SYMBOL(div64_u64_rem);
 #endif
 
-/**
+/*
  * div64_u64 - unsigned 64bit divide with 64bit divisor
  * @dividend:	64bit dividend
  * @divisor:	64bit divisor
@@ -163,11 +157,6 @@ u64 div64_u64(u64 dividend, u64 divisor)
 EXPORT_SYMBOL(div64_u64);
 #endif
 
-/**
- * div64_s64 - signed 64bit divide with 64bit divisor
- * @dividend:	64bit dividend
- * @divisor:	64bit divisor
- */
 #ifndef div64_s64
 s64 div64_s64(s64 dividend, s64 divisor)
 {