msr.4, veth.4, packet.7, sched.7, unicode.7: Remove redundant .PP

.PP and .IP are redundant just before .SH or .SS.
Remove them.

$ find man? -type f \
  |xargs sed -i '/^\.[IP]P$/{N;s/.*\n\(\.S[HS]\)/\1/}';

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man4/msr.4

@@ -56,7 +56,6 @@ to load it explicitly before use:
 $ modprobe msr
 .EE
 .in
-.PP
 .SH SEE ALSO
 Intel Corporation Intel 64 and IA-32 Architectures
 Software Developer's Manual Volume 3B Appendix B,

man4/veth.4

@@ -98,7 +98,6 @@ NIC statistics:
 16: ve_B@ve_A: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc ...
 .EE
 .in
-.PP
 .SH "SEE ALSO"
 .BR clone (2),
 .BR network_namespaces (7),

man7/packet.7

@@ -550,7 +550,6 @@ In addition, other errors may be generated by the low-level driver.
 is a new feature in Linux 2.2.
 Earlier Linux versions supported only
 .BR SOCK_PACKET .
-.PP
 .SH NOTES
 For portable programs it is suggested to use
 .B AF_PACKET

man7/sched.7

@@ -686,7 +686,6 @@ that is, no CPU time is set aside for non-real-time processes
 The default value in this file is 950,000 (0.95 seconds),
 meaning that 5% of the CPU time is reserved for processes that
 don't run under a real-time or deadline scheduling policy.
-.PP
 .SS Response time
 A blocked high priority thread waiting for I/O has a certain
 response time before it is scheduled again.

man7/unicode.7

@@ -190,7 +190,6 @@ and
 .BR wcwidth (3)
 tells, how many positions (0\(en2) the cursor is advanced by the
 output of a character.
-.PP
 .SS Private Use Areas (PUA)
 In the Basic Multilingual Plane,
 the range 0xe000 to 0xf8ff will never be assigned to any characters by