scripts: Remove export_report.pl

This script has been broken for 5 years with no user complaints.

It first had its .mod.c parser broken in commit a3d0cb0 ("modpost:
use __section in the output to *.mod.c"). Later, it had its object file
enumeration broken in commit f65a486 ("kbuild: change module.order
to list *.o instead of *.ko"). Both of these changes sat for years with
no reports.

Rather than reviving this script as we make further changes to `.mod.c`,
this patch gets rid of it because it is clearly unused.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

Makefile

@@ -1602,7 +1602,6 @@ help:
 	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
 	@echo  '  versioncheck    - Sanity check on version.h usage'
 	@echo  '  includecheck    - Check for duplicate included header files'
-	@echo  '  export_report   - List the usages of all exported symbols'
 	@echo  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
 	@echo  '  clang-analyzer  - Check with clang static analyzer'
@@ -2015,7 +2014,7 @@ endif
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
-PHONY += includecheck versioncheck coccicheck export_report
+PHONY += includecheck versioncheck coccicheck
 
 includecheck:
 	find $(srctree)/* $(RCS_FIND_IGNORE) \
@@ -2030,9 +2029,6 @@ versioncheck:
 coccicheck:
 	$(Q)$(BASH) $(srctree)/scripts/$@
 
-export_report:
-	$(PERL) $(srctree)/scripts/export_report.pl
-
 PHONY += checkstack kernelrelease kernelversion image_name
 
 # UML needs a little special treatment here.  It wants to use the host