Ruby: More descriptive message buffer connection fatal
Ruby: More descriptive message buffer connection fatal

When connecting message buffers between Ruby controllers, it is
easy to mistakenly connect multiple controllers to the same message
buffer. This patch prints a more descriptive fatal message than the
previous assert statement in order to facilitate easier debugging.

markoshorro/gem5,briancoutinho0905/2dsampling,zlfben/gem5,powerjg/gem5-ci-test,cancro7/gem5,joerocklin/gem5,kaiyuanl/gem5,joerocklin/gem5,yb-kim/gemV,joerocklin/gem5,sobercoder/gem5,KuroeKurose/gem5,briancoutinho0905/2dsampling,gem5/gem5,KuroeKurose/gem5,TUD-OS/gem5-dtu,HwisooSo/gemV-update,SanchayanMaity/gem5,Weil0ng/gem5,powerjg/gem5-ci-test,cancro7/gem5,TUD-OS/gem5-dtu,kaiyuanl/gem5,yb-kim/gemV,yb-kim/gemV,rjschof/gem5,austinharris/gem5-riscv,cancro7/gem5,samueldotj/TeeRISC-Simulator,HwisooSo/gemV-update,gem5/gem5,sobercoder/gem5,sobercoder/gem5,sobercoder/gem5,austinharris/gem5-riscv,rjschof/gem5,KuroeKurose/gem5,markoshorro/gem5,samueldotj/TeeRISC-Simulator,SanchayanMaity/gem5,briancoutinho0905/2dsampling,gedare/gem5,aclifton/cpeg853-gem5,Weil0ng/gem5,sobercoder/gem5,samueldotj/TeeRISC-Simulator,briancoutinho0905/2dsampling,TUD-OS/gem5-dtu,HwisooSo/gemV-update,zlfben/gem5,kaiyuanl/gem5,gedare/gem5,gedare/gem5,austinharris/gem5-riscv,kaiyuanl/gem5,yb-kim/gemV,gem5/gem5,TUD-OS/gem5-dtu,Weil0ng/gem5,joerocklin/gem5,KuroeKurose/gem5,TUD-OS/gem5-dtu,markoshorro/gem5,TUD-OS/gem5-dtu,austinharris/gem5-riscv,rjschof/gem5,briancoutinho0905/2dsampling,qizenguf/MLC-STT,aclifton/cpeg853-gem5,rjschof/gem5,cancro7/gem5,markoshorro/gem5,cancro7/gem5,rjschof/gem5,aclifton/cpeg853-gem5,KuroeKurose/gem5,gedare/gem5,gem5/gem5,powerjg/gem5-ci-test,austinharris/gem5-riscv,samueldotj/TeeRISC-Simulator,aclifton/cpeg853-gem5,joerocklin/gem5,aclifton/cpeg853-gem5,zlfben/gem5,Weil0ng/gem5,cancro7/gem5,austinharris/gem5-riscv,gem5/gem5,SanchayanMaity/gem5,briancoutinho0905/2dsampling,gem5/gem5,HwisooSo/gemV-update,yb-kim/gemV,rallylee/gem5,HwisooSo/gemV-update,austinharris/gem5-riscv,gedare/gem5,qizenguf/MLC-STT,kaiyuanl/gem5,HwisooSo/gemV-update,powerjg/gem5-ci-test,gem5/gem5,TUD-OS/gem5-dtu,SanchayanMaity/gem5,qizenguf/MLC-STT,samueldotj/TeeRISC-Simulator,rjschof/gem5,sobercoder/gem5,briancoutinho0905/2dsampling,rallylee/gem5,rallylee/gem5,HwisooSo/gemV-update,powerjg/gem5-ci-test,joerocklin/gem5,aclifton/cpeg853-gem5,markoshorro/gem5,qizenguf/MLC-STT,KuroeKurose/gem5,zlfben/gem5,Weil0ng/gem5,rjschof/gem5,yb-kim/gemV,rallylee/gem5,sobercoder/gem5,rallylee/gem5,zlfben/gem5,SanchayanMaity/gem5,samueldotj/TeeRISC-Simulator,powerjg/gem5-ci-test,SanchayanMaity/gem5,Weil0ng/gem5,cancro7/gem5,kaiyuanl/gem5,markoshorro/gem5,zlfben/gem5,joerocklin/gem5,markoshorro/gem5,yb-kim/gemV,aclifton/cpeg853-gem5,KuroeKurose/gem5,Weil0ng/gem5,rallylee/gem5,joerocklin/gem5,qizenguf/MLC-STT,qizenguf/MLC-STT,powerjg/gem5-ci-test,kaiyuanl/gem5,SanchayanMaity/gem5,rallylee/gem5,yb-kim/gemV,zlfben/gem5,qizenguf/MLC-STT,samueldotj/TeeRISC-Simulator,gedare/gem5,gedare/gem5