dev: Fix style in pktfifo.hh.

Put return types of multi-line functions on their own line.

Change-Id: I6c9cade720bd1c7aaa09c42b838c9bd83da7bc8f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48925
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/dev/net/pktfifo.hh

@@ -64,7 +64,8 @@ struct PacketFifoEntry
     {
     }
 
-    void clear()
+    void
+    clear()
     {
         packet = NULL;
         number = 0;
@@ -120,7 +121,8 @@ class PacketFifo
 
     EthPacketPtr front() { return fifo.begin()->packet; }
 
-    bool push(EthPacketPtr ptr)
+    bool
+    push(EthPacketPtr ptr)
     {
         assert(ptr->length);
         assert(_reserved <= ptr->length);
@@ -137,7 +139,8 @@ class PacketFifo
         return true;
     }
 
-    void pop()
+    void
+    pop()
     {
         if (empty())
             return;
@@ -149,7 +152,8 @@ class PacketFifo
         fifo.pop_front();
     }
 
-    void clear()
+    void
+    clear()
     {
         for (iterator i = begin(); i != end(); ++i)
             i->clear();
@@ -158,7 +162,8 @@ class PacketFifo
         _reserved = 0;
     }
 
-    void remove(iterator i)
+    void
+    remove(iterator i)
     {
         if (i != fifo.begin()) {
             iterator prev = i;
@@ -177,14 +182,16 @@ class PacketFifo
 
     bool copyout(void *dest, unsigned offset, unsigned len);
 
-    int countPacketsBefore(const_iterator i) const
+    int
+    countPacketsBefore(const_iterator i) const
     {
         if (i == fifo.end())
             return 0;
         return i->number - fifo.begin()->number;
     }
 
-    int countPacketsAfter(const_iterator i) const
+    int
+    countPacketsAfter(const_iterator i) const
     {
         auto end = fifo.end();
         if (i == end)
@@ -192,7 +199,8 @@ class PacketFifo
         return (--end)->number - i->number;
     }
 
-    void check() const
+    void
+    check() const
     {
         unsigned total = 0;
         for (auto i = begin(); i != end(); ++i)