package/lsof: change _LICENSE_FILES to use COPYING

Commit e3322e2c7 "lsof: add license info" added the package license
info. At that time, lsof was at version 4.85. The package was not
including a dedicated license file. Instead, the license text was
copied in many files (source files, readmes, ...). It was then decided
to use the small source file "dialects/linux/dproto.h".

Recently, lsof added a COPYING license file. See [1]. This commit was
first included in lsof version 4.97.0. We can now use this file.

The license file hash is updated due to formatting changes. As a side
note, the copyright year in source file was 1997 (see [2]), whereas in
the new license file it is 2002. Source files have different copyright
dates, and can be as old as 1994, for example in [3]. The rest of the
license text remains unchanged.

[1] https://github.com/lsof-org/lsof/commit/62dab61cae3ca9e4d41ec573ae5cda0c5689c326
[2] https://github.com/lsof-org/lsof/blob/4.98.0/dialects/linux/dproto.h#L9
[3] https://github.com/lsof-org/lsof/blob/4.98.0/arg.c#L7

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/lsof/lsof.hash

@@ -1,3 +1,3 @@
 # Locally calculated
 sha256  80308a614508814ac70eb2ae1ed2c4344dcf6076fa60afc7734d6b1a79e62b16  lsof-4.98.0.tar.gz
-sha256  32a728188b19bf86917659d904ab29d0a294b4506e1c98b8b7f1c70ab4975fe1  dialects/linux/dproto.h
+sha256  225222ff9bf38abc2cef7205e9b05c60935efa9ec28d1fd01e503c9316088718  COPYING

package/lsof/lsof.mk

@@ -7,9 +7,7 @@
 LSOF_VERSION = 4.98.0
 LSOF_SITE = $(call github,lsof-org,lsof,$(LSOF_VERSION))
 LSOF_LICENSE = lsof license
-# License is repeated in each file, this is a relatively small one.
-# It is also defined in 00README, but that contains a lot of other cruft.
-LSOF_LICENSE_FILES = dialects/linux/dproto.h
+LSOF_LICENSE_FILES = COPYING
 LSOF_CPE_ID_VENDOR = lsof_project
 
 ifeq ($(BR2_PACKAGE_LIBTIRPC),y)