revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/compat/regex/regex.h

@@ -41,11 +41,6 @@
 extern "C" {
 #endif
 
-#define regcomp git_regcomp
-#define regexec git_regexec
-#define regerror git_regerror
-#define regfree git_regfree
-
 /* The following two types have to be signed and unsigned integer type
    wide enough to hold a value of a pointer.  For most ANSI compilers
    ptrdiff_t and size_t should be likely OK.  Still size of these two
@@ -327,7 +322,7 @@ typedef enum
   /* POSIX regcomp return error codes.  (In the order listed in the
      standard.)  */
   REG_BADPAT,		/* Invalid pattern.  */
-  REG_ECOLLATE,		/* Invalid collating element.  */
+  REG_ECOLLATE,		/* Inalid collating element.  */
   REG_ECTYPE,		/* Invalid character class name.  */
   REG_EESCAPE,		/* Trailing backslash.  */
   REG_ESUBREG,		/* Invalid back reference.  */